RNAA and AMS of iodine-129 in environmental materials - comparison of analytical methods and quality assurance

Radiochemical neutron activation analysis (RNAA) accelerator mass spectrome try (AMS) are discussed with respect to their capabilities to analyze I-129 in environmental samples. Respective analytical protocols are described wi th special emphasis of quality assurance and of contamination and blank con trol. Particular problems of the analysis of I-129 (and I-127) nye addresse d and discussed in the context of the results of a first international AMS round robin exercise for low-level I-129 samples. Comparative determination s by RNAA and AMS were performed for several materials including IAEA soil- 375 which is the only certified reference material for I-129. AS a new low- level reference material for I-129 the NIST SRM 2709 San Joaquin Soil is pr oposed. A short survey on the present situation and on future tendencies of I-129 in the European environment is given.